import turtle

x1,y1=100,100
x2,y2=100,-100
x3,y3=-100,-100
x4,y4=-100,100

# 绘制海龟图片
turtle.penup()
turtle.goto(x1,y1)
turtle.pendown()
turtle.goto(x2,y2)
turtle.goto(x3,y3)
turtle.goto(x4,y4)

# 计算起点到终点的距离
distance = ((x1-x2)**2+(y1-y2)**2)**0.5
turtle.write( distance)
turtle.done()

